Seasonal variations in composting process of dead poultry birds.

Composting of dead birds with caged layer manure (CLM) and farm yard manure (FYM) was carried out to study the feasibility of composting as an alternative for disposal in Tamil Nadu State, India. The dead birds were sequentially layered with manure substrate and carbon source as per recipes formulated in mini-compost bins (4 x 4 x 4 feet). The temperature profile of both CLM and FYM group reached the peak by second week of composting and started declining steadily. The temperature profile was better during summer and monsoon and bins were able to maintain temperature above 60 degrees C (thermophilic) for 3-4 weeks. Season had no influence on attainment of peak temperature and it ranged between 51.8 and 70.4 degrees C. The persistency of thermophilic temperature (above 55 degrees C) was prolonged during summer (17.5-65 days) followed by monsoon (24-39 days) and winter (15.5-21.5 days). No putrefied or obnoxious odour or fly menace was observed during all the seasons of composting. The composting process took 107-127.5 days to finish during summer, 84.5-91 days in monsoon and 61.5-73.5 days in winter. The FYM was able to retain moisture higher (41-54% at the end of primary stage and 27.5-48.2% at the end of secondary stage) than CLM group (17.5-39.3% at primary stage and 20.4-33.5% in secondary stage). Weight reduction was more in FYM group (31.8-58.7%) than CLM group (19.3-48.6%). The volume reduction was uniform in all the seasons, it ranged between 39% and 59.3%.